The present invention relates to a seat cushion airbag apparatus that inflates an airbag installed in a seat portion of a vehicle seat with inflation fluid such as inflation gas, thereby raising the seat face to restrain an object to be restrained such as an occupant seated in the seat portion against forward movement.
When an impact due to a front collision is applied to a vehicle from the front, the lumbar region of an occupant restrained to a vehicle seat by a seat belt device may be disengaged from the lap belt portion and move forward. This is known as a “submarine phenomenon.” Various measures against the submarine phenomenon have been proposed.
For example, Japanese Laid-Open Patent Publication No. 2007-238016 discloses a seat cushion airbag apparatus applied to a vehicle seat having a seat portion. The seat portion is structured such that a seat cushion is supported from below by a support portion of a seat frame. The support portion includes spring members for elastically supporting the seat cushion from below and hooks for securing the spring members.
The seat cushion airbag apparatus has an accommodation case (base) having an upper opening. The accommodation case is located forward of the support portion of the seat frame. The accommodation case accommodates an inflation fluid generator (inflator) arranged therein. An airbag is also arranged in the accommodation case. The airbag is inflated with inflation fluid (high-pressure gas) supplied by the inflation fluid generator. Further, a contact preventing member is rotationally supported at the upper end of the accommodation case. The contact preventing member closes the upper opening of the accommodation case when no impact is applied from the front of the vehicle and the seat cushion airbag apparatus is not activated.
According to the above seat cushion airbag apparatus, when an impact is applied from the front of the vehicle, the inflation fluid generator supplies inflation fluid to the airbag, so that the airbag is deployed and inflated while being unfolded. The airbag, which is being deployed and inflated upward, raises the contact preventing member. This rotates the contact preventing member rearward to be overlapped with a front portion of the support portion. The airbag is deployed and inflated rearward in a space between the seat cushion and the set of the contact preventing member and the support portion. The airbag thus pushes up the seat cushion so that the seat face is raised to restrain the occupant in the seat against forward movement. At this time, the contact preventing member prevents the airbag and the support portion of the seat frame from contacting each other so that the airbag is not damaged by contact with the support portion.